KR102158770B1 - Monitoring device for dismantling of nuclear facilities - Google Patents

Abstract

According to an embodiment of the present invention, provided is a monitoring device for dismantling nuclear facilities which can safely perform dismantling operation. The monitoring device for dismantling nuclear facilities comprises: a grid structure including a plurality of crossbars arranged at regular intervals and a plurality of vertical bars intersecting the crossbar and arranged at regular intervals; and a measuring unit installed at an intersection unit of the crossbar and the vertical bar. The grid structure is configured to be detachable to a wall and the measuring unit includes at least one of a turbidimeter and a radiation dose meter.

Description

Monitoring device for dismantling nuclear facilities {MONITORING DEVICE FOR DISMANTLING OF NUCLEAR FACILITIES}

The present invention relates to a monitoring device, and more particularly to a monitoring device for dismantling a nuclear facility for monitoring a cavity during the dismantling operation of a nuclear facility.

In general, nuclear facilities such as nuclear power plants are disposed of when operation is terminated, and such disposal measures can be carried out in the order of system decontamination, nuclear fuel safe storage, and dismantling.

Demolition In demolition, the building is demolished after the internal piping and equipment are removed. At this time, it is necessary to ensure that radioactive substances are not scattered to the outside during dismantling and demolition, and that workers engaged in dismantling and demolition are not exposed to radiation.

To this end, when dismantling the reactor pressure vessel, which is the most difficult to dismantle, water was filled in the cavity, the structure inside the furnace was taken out and dismantled by a cutting device, and the reactor pressure vessel was cut and taken out by a cutting device.

However, such dismantling has a problem in that it is difficult to secure a view because the number of steps of the dismantling operation is large and the dismantling period is long, so that the operator is likely to be exposed to radioactivity.

Accordingly, the present invention provides a monitoring device for dismantling a nuclear power plant that can safely proceed with the dismantling operation by securing a view in the air or underwater in the cavity while preventing the worker from being exposed to radiation during the dismantling process.

The monitoring device for nuclear power dismantling according to an embodiment of the present invention is a grid structure including a plurality of crossbars and crossbars arranged at regular intervals and a plurality of vertical bars arranged at regular intervals, at the intersection of the crossbar and the vertical bar. It includes a measuring unit installed, the grid structure is configured to be detachable to the wall, and the measuring unit includes at least one of a turbidimeter and a radiation dose meter.

The measurement unit may further include at least one of an electrical conductivity measurement sensor, a temperature sensor, a pressure sensor, an optical sensor, an acoustic sensor, a pH sensor, a position sensor, and an oxidation-reduction potential sensor.

The measurement unit may further include a communication unit capable of wired or wireless communication, and the communication unit may transmit the information measured by the measurement unit to a control unit that receives, analyzes, and displays the information measured by the measurement unit.

The width of the intersection may be wider than the width of the crossbar and the vertical bar.

The fixing device may be a screw or an anchor.

The crossbar and the vertical bar may be made of carbon steel or stainless steel.

The grid structure further includes a fixing device for attaching the grid structure to the external structure, and the fixing device may be a screw or an anchor.

When the monitoring device for nuclear power dismantling as in the embodiment of the present invention is used, a monitoring device can be easily installed inside the cavity when dismantling a nuclear power plant, so that the internal state of the cavity can be checked.

Therefore, the dismantling operation can be performed according to the internal state of the cavity, and the operator can be put in an efficient and safe state, thereby protecting the operator from exposure.

1 is a cross-sectional view showing a part of a nuclear facility in which a monitoring device for dismantling a nuclear power plant is installed according to an embodiment of the present invention.
2 is a schematic diagram of a monitoring device for dismantling a nuclear power plant according to an embodiment of the present invention.
3 and 4 are schematic views of a monitoring device for dismantling a nuclear power plant according to another embodiment of the present invention.
5 is a flowchart illustrating a method of using a monitoring device for dismantling a nuclear power plant according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. The present invention may be implemented in various different forms, and is not limited to the embodiments described herein.

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

In addition, throughout the specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated.

Hereinafter, a monitoring device for dismantling a nuclear power plant according to an embodiment of the present invention will be described with reference to the drawings.

1 is a cross-sectional view showing a part of a nuclear facility in which a monitoring device for dismantling a nuclear power plant is installed according to an embodiment of the present invention.

As shown in FIG. 1, a nuclear facility 1000 according to an embodiment of the present invention includes a reactor pressure vessel 100, a plurality of pipes 200 directly connected to the reactor pressure vessel 100, and a reactor pressure vessel ( 100) and the pipes 200, including the bioprotective concrete 300 and the crane 400 supporting the reactor pressure vessel 100, and may further include a variety of known configurations.

The nuclear facility may be a pressurized light water reactor type (PWR) nuclear power plant, but is not limited thereto, and may be a boiling light water reactor type (BWR) nuclear power plant.

Pressurized light water reactor type nuclear power plants use hard water as a coolant and moderator, and use uranium 235 concentrated to about 2% to 4% as nuclear fuel.

Pressurized light water reactor type nuclear power plants return the heat generated by nuclear fission within the reactor to a steam generator and return the turbine to water through a condenser after turning the turbine with steam generated from the facility and steam generator related to the reactor system for heat exchange. It can be divided into facilities related to the turbine and generator systems circulating to the generator.

In general, coolant (hard water), which is a heat transfer medium of a nuclear reactor system, is heated to about 320°C in a nuclear reactor and pressurized to about 153 atmospheres so that it does not boil. Equipment constituting the system includes a pressurizer that adjusts pressure to maintain a constant enthalpy, and a coolant pump that circulates coolant between the reactor and the steam generator.

The system in which the steam generated by the steam generator rotates the turbine and generates power from the generator connected to the turbine shaft may be the same as that of a general thermal power plant.

The reactor pressure vessel 100 may be a pressurized light water reactor type, but is not limited thereto. For example, the reactor pressure vessel 100 may be a boiling light water reactor type. The inner wall of the reactor pressure vessel 100 may be formed with a protrusion 110 supporting various known types of cores.

The plurality of pipes 200 may be connected to known various types of steam generators, and hot water may flow through some of the pipes 200, and cold water may flow through the remaining pipes, but the present invention is not limited thereto.

The bioprotective concrete 300 forms a space in which the reactor pressure vessel 100 is placed and a closed space to prevent radiation from leaking to the outside, and the upper part may have a dome shape.

The bioprotective concrete 300 includes a cavity 500 having an empty inside, and the cavity 500 has a first cavity 51 and a second cavity 52 that are internal spaces of different depths and volumes.

The reactor pressure vessel 100 may be located in the first cavity 51. The first cavity 51 is a lower space 51a in which the reactor pressure vessel 100 is inserted and fixed, and an upper space 51b that is positioned above the lower space 51a to form a space in which the reactor pressure vessel 100 moves. Includes.

The second cavity 52 is connected to the upper space 51b of the first cavity 51 and may be formed deeper than the upper space 51b. The second cavity 52 is a work space for dismantling the reactor pressure vessel 100 when the reactor pressure vessel 100 is dismantled, and when the nuclear pressure vessel 100 separated from the lower space 51a or the dismantling operation It provides a space for the generated components to be placed.

The dismantling operation is a series of operations in which an internal structure such as the reactor pressure vessel 100 or pipe is cut and safely discharged to the outside.The reactor pressure vessel 100 or pipe using a cutting means such as a circular saw or wire saw It may include the operation of cutting the internal structure such as movable.

During the dismantling operation, the first cavity 51 and the second cavity 52 may be filled with water to prevent exposure of workers due to radiation generated from internal structures and parts.

Water shields radioactivity and prevents by-products generated during the dismantling operation from scattering, thereby preventing the by-products from being suspended in the cavity 500 or in contact with workers. At this time, the water used may be a general constant water, not hard water.

The water level is high enough to provide adequate shielding to keep the radiation level within acceptable limits when the fuel assembly is completely removed from the container. Accordingly, an underwater area and an air area may exist together inside the cavity 500.

The water filled in the first cavity 51 and the second cavity 52 may be discharged to the outside according to the underwater state, and then undergo a re-supply cycle through a purification process using a filter system or the like. In addition, the filter may be installed in a floating state in water, and such a filter may be replaced according to the underwater state.

The crane 400 is located above the bioprotective concrete 300, and the crane 400 may be the crane 400 used when the initial nuclear facility was installed, but is not limited thereto.

The crane 400 may move parts that need to be dismantled or disassembled parts from the first cavity 51 to the second cavity 52 or to a third discharge area during the dismantling operation of the reactor pressure vessel 100.

Meanwhile, a monitoring device may be installed on the inner wall of the cavity 500, that is, the upper space 51b and the second cavity 52, and the monitoring device will be described with reference to FIGS. 2 to 4.

2 is a schematic view of a monitoring device for nuclear power dismantling according to an embodiment of the present invention, and FIGS. 3 and 4 are schematic views of a monitoring device for dismantling a nuclear power plant according to another embodiment of the present invention.

As shown in Figure 2, the monitoring device 600 for dismantling a nuclear power plant according to an embodiment of the present invention includes a lattice structure 601, a measurement unit 602 installed on the lattice of the lattice structure 601, respectively. do.

The measuring unit 602 may be fixed to the grid structure using a separate member such as a cable tie, but is not limited thereto and may be fixed by a method such as welding.

The monitoring device 600 may be detachably attached to the inner wall of the cavity 500 as needed, and after fixing it to the inner wall of the cavity 500 through a fixing device 603 such as screws or anchors (see FIG. 1), the use is terminated. It can be removed after separating it from the inner wall. At this time, a structure such as an anchor may be installed on the inner wall of the cavity 500 in advance when designing a nuclear power plant or before a dismantling operation.

Separate rings can be connected to the lattice structure, or screws can be directly inserted into the lattice structure and fastened to the anchor.

As such, since the monitoring device 600 according to an embodiment of the present invention is detachable to the inner wall of the cavity 500, the monitoring device 600 may be installed in plural according to the shape and size of the cavity 500. .

In addition, although FIG. 1 shows that the monitoring device is installed on the inner wall of the cavity, it is not limited thereto, and various external structures for monitoring underwater or air conditions, for example, external structures such as a wastewater tank storing radiation contaminated wastewater Can also be installed.

In addition, in FIG. 2, the lattice structure 601 is illustrated as an example in which the lattice structure 601 is substantially rectangular, but is not limited thereto and may be formed in various shapes such as a circle or a polygon according to the internal structure of the cavity.

The lattice structure 601 is formed by crossing the crossbar 61 extending in the first direction and the vertical bar 62 extending in the second direction, and the crossbar 61 and the vertical bar 62 may be metal wires.

The lattice structure 601 is not corroded by water filled in the cavity, and may be made of a material resistant to radioactive materials, and may be made of, for example, a material such as carbon steel or stainless steel used as a reactor pressure vessel or a pipe connected thereto. In addition, it may be made of a polymer material other than metal.

A measuring unit 602 may be installed at the intersection S of the crossbar 61 and the vertical bar 62.

The measuring part 602 can be attached on the cross section (S), and when forming the crossbar and the vertical bar with a metal wire, it may not be easy to attach the measuring part because the line width is narrow, so a metal strip having a certain width By forming a crossbar and a vertical bar, it is possible to increase the area of the area to which the measurement part is attached to facilitate attachment.

In addition, in order to facilitate the attachment of the measurement unit 602, the width W1 of the crossbar and the vertical bar at the intersection S as in the monitoring device 610 of FIG. 3 is larger than the width W2 of the other part. Can be formed. That is, if the width of the cross section S is formed to be wider than the cross bar or the vertical bar, the area to which the measurement unit is attached can be increased to facilitate attachment.

Since the size of the measuring unit may vary depending on the sensors included therein, the grating structure may be selected according to the number or size of the sensors.

As shown in FIG. 2, the measurement unit 602 of the monitoring device 600 may be installed for each intersection (S), but is not limited thereto, and as in the monitoring device 620 of FIG. 4, a certain number of intersections ( Each S) measurement unit 602 can be provided.

The measurement units 602 may be disposed at various intervals according to the measurement capability of the measurement unit 602.

In addition, in the present invention, since the grating structure is formed so that the intersections are arranged at regular intervals, and the measurement units are attached to the intersections, the sensors can be easily arranged at regular intervals without measuring a separate distance.

Meanwhile, the measurement unit 602 may include a plurality of sensors (not shown) and a communication unit (not shown).

The sensor may be a sensor that measures characteristics of air and water in order to monitor the cavity environment, that is, conditions in air and water. The sensor may include a radiation dosimeter for measuring radiation dose and a turbidity meter for measuring turbidity.

In the case of installation in a nuclear facility, since the air or underwater conditions inside the cavity are important, the example including a radiation dosimeter and a turbidimeter has been exemplified, but is not limited thereto, and depending on the environment in which the monitoring device according to an embodiment of the present invention is installed At least one of an electrical conductivity measurement sensor, a temperature sensor, a pressure sensor, an optical sensor, an acoustic sensor, a pH sensor, and an ORP (oxidation-reduction potential) sensor may be further included.

The radiation dosimeter may be an automatic dosimeter, but is not limited thereto, and may include various types of radiation dosimeters capable of measuring a dose in real time.

The sensor may include a location sensor capable of detecting location information of a point where the sensor is installed. Accordingly, the location information of the point where the sensor is installed can be transmitted to the control unit 70 (see FIG. 1 ), and the control unit 70 can grasp the underwater state in real time for each location of the cavity 500.

Therefore, the underwater (or in the air) state according to the location can be specifically identified, so that the dismantling operation can be carried out more safely when dismantling.

When the information to be measured is different according to the location, the measurement unit 602 may arrange the measurement unit 602 including different sensors according to the location. For example, a turbidimeter and a sensor for measuring electrical conductivity may be installed at the cross section S located underwater, and only a radiation dose meter may be installed at the cross section S located outside the water surface.

The measurement unit 602 may measure the amount of radiation, turbidity, and electrical conductivity in the water in real time, and transmit it to the control unit 70 through a communication unit capable of wired or wireless communication. For example, the communication unit ), it may be configured to enable short-range or long-distance wireless communication through a mobile communication network (3G, LTE), or the like.

The control unit 70 analyzes the information transmitted from the measurement unit 602, and may be a computer or a tablet having a display unit displaying the analyzed information. It can be located outside or portable so that the operator can easily monitor it anywhere.

As described above, when the monitoring device is used as in the exemplary embodiment of the present invention, it is possible to safely perform the dismantling work by preventing the worker from being exposed during the dismantling work of the nuclear facility.

5 is a flowchart illustrating a method of using a monitoring device for dismantling a nuclear power plant according to an embodiment of the present invention.

Reference numerals of the monitoring device for dismantling a nuclear power plant refer to the reference numerals of FIGS. 1 and 2 described above.

As shown in FIG. 5, the method of using the monitoring device for nuclear power dismantling according to an embodiment of the present invention includes the steps of installing a monitoring device on the inner wall of the cavity (S100), and collecting information by measuring characteristics inside the cavity. Step S102, the step of transmitting the collected information to the control unit through the communication unit (S104), the control unit includes a step (S106) of generating a warning or a follow-up task by comparing with the information based on the input information.

The monitoring device 600 may fix the monitoring device to the inner wall of the cavity 500 through the fixing device 603 (S100). The monitoring device can be installed during the dismantling process and before filling.

The monitoring device 600 may be partially or entirely located underwater, and collects various types of information through a sensor of the measurement unit 602 (S102).

The collected information is transmitted to the control unit 70 through the communication unit (S104), and the control unit 70 analyzes the input information and transmits it to the display unit (S106). In this case, the information transmitted to the display unit may include a warning signal when the reference value is exceeded compared to the preset value, but is not limited thereto, and may include the content of a designated follow-up operation according to the set value. When the operator determines whether there is a follow-up task and generates it, the information may be displayed on the display as a number that the operator can recognize.

Conventionally, in order to monitor the underwater condition, the operator individually inserts a sensor into the water to identify the underwater condition. have. Therefore, it is possible to grasp the underwater condition through the transmitted information, and plan and proceed with subsequent work according to the underwater condition.

For example, if the underwater turbidity is higher than the reference value, the underwater view is not secured and the dismantling operation cannot proceed any more. Accordingly, a work that can be performed only when an underwater view is secured, such as a cutting operation, is stopped, and a filter replacement or purification work using an internal filter system is performed to secure the underwater view, and then the dismantling work can proceed.

Such a subsequent operation may be determined by the operator through information displayed on the display unit, but may be compared with a preset value through the control unit to command the subsequent operation.

On the other hand, when the amount of radiation measured when the operator is inputted and the amount of radiation measured exceeds the reference value, an alarm is sounded to prevent the operator from being injected into the position where the radiation amount was exceeded, thereby preventing the worker from being exposed.

In the present invention, since a position sensor is included, processing necessary for subsequent work at an accurate position based on information according to the position, for example, when a filter is located in a plurality of areas, the position of the filter that needs to be replaced is identified, and then the filter is replaced. Alternatively, the input of the worker may be determined. When the filter is installed in a floating state in the water, turbidity can be measured according to the location, so the turbidity can be improved by replacing the filter located in the area according to the turbidity.

In the above, preferred embodiments of the present invention have been described, but the present invention is not limited thereto, and it is possible to implement various modifications within the scope of the claims, the detailed description of the invention, and the accompanying drawings. It is natural to fall within the scope of

100: reactor pressure vessel
200: pipes
300: bioconcrete
400: crane
500: cavity
600: monitoring device

Claims (6)

A lattice structure including a plurality of crossbars arranged at regular intervals and a plurality of vertical bars intersecting the crossbars and arranged at regular intervals,
Measurement unit installed at the intersection of the crossbar and the vertical bar
Including,
The grid structure is configured to be detachable to the wall,
The monitoring device for dismantling a nuclear power plant including at least one of a turbidimeter and a radiation dose meter. In claim 1,
The measuring unit further comprises at least one of an electrical conductivity measurement sensor, a temperature sensor, a pressure sensor, an optical sensor, an acoustic sensor, a pH sensor, a position sensor, and an oxidation-reduction potential sensor. In claim 1,
The measurement unit is a communication unit capable of wired or wireless communication
Including more,
The communication unit is a monitoring device for dismantling a nuclear power plant that delivers the information measured by the measurement unit to a control unit that receives, analyzes, and displays the information measured by the measurement unit. In claim 1,
The width of the intersection is wider than the width of the crossbar and the vertical bar for nuclear power dismantling monitoring device. In claim 1,
The crossbar and the vertical bar are a monitoring device for nuclear power dismantling made of carbon steel or stainless steel. In claim 1,
The grid structure is a fixing device for attaching the grid structure to an external structure
Including more,
The fixing device is a screw or anchor monitoring device for nuclear power dismantling.

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